Buy Solar Panels in less than 12 minutes, in the comfort of your home

Editorial: This is an archived blog post I (plus much assitance from the team) wrote early in my career at Big Sun. Sadly, most of the helpful associated images are lost from the original blog post.

With the launch of our new community solar program for CPS Energy, Big Sun Community Solar, a major focus is providing the best experience for customers as they reserve their panels. We measure our success based on two questions: How is the general user experience for our Design Tool and are we educating customers who are unfamiliar with community solar or solar in general? Traditionally the purchase cycle for rooftop solar panels has been a long process. From identifying qualified solar contractors and reviewing historic energy bill to determine the right size system to engineering, permitting and construction, the process takes 45 to 60 days for both customers and solar companies. Never has there been a platform where a customer can customize their solar panel system in real time using their actual consumption data AND buy them - until now!

With the partnership of CPS Energy and Go Smart Solar for the Big Sun Community Solar Program, an API was created that used modern methods (i.e. RESTful HTTPS architecture) to verify customer eligibility for the program. Additionally the API transfers the users previous 12 months of bill and consumption data which is then displayed in an interactive chart; which was previously received through a series of hardcopy permissions forms, emails and individual spreadsheets. Now, using the same functionality as Tesla's Design Studio, customers can compare their historic energy usage to community solar membership, see the potential costs and savings in real-time and make an educated buying decision from the comfort of their home. No more pushy sales calls, robo dialers or unsolicited door knockers. With CPS Energy sponsoring the program - you know it trustworthy.

What is an API?

If you’re unfamiliar with APIs (Application Program Interfaces), don’t worry, you’re not alone! You interact with them anytime you are using the web. An API is a set of code that allows platform (or devices) to communicate. This code consists of routines, protocols, and functions that expedite and streamline the communication. For instance, Google Map API allows 3rd party applications to implement Google's map interface, features and data.

APIs are key components to the modern web and the way software applications transmit data to one another. They have also made great advances for the way companies securely communicate information back and forth.

Pre-fancy-API: How we planned to communicate consumption history?

Originally onboarding customers would have been a lengthy manual process for the entire Big Sun team. When a customer initially used the Big Sun Design Tool, we asked them to estimate their previous month’s bill. Using that information and an algorithm we developed in house, we estimated their annual electric bill. Our customer would be able to reserve panels to offset up to 120% of their estimated annual electric bill. We then asked the user to sign a permission form for CPS Energy which we submitted via email. Once CPS Energy sent back the consumption history we verified the offset percentage and finalized the system size and customer agreement.

Separately, we needed to verify our customer’s eligibility for the program using SFTP (SSH File Transfer Protocol). On an interval schedule (every hour or so) CPS Energy's servers would grab the customer verification file with customers’ information on our side and manually check each customer’s eligibility for the program. Finally CPS Energy would create a file marking if the customer was eligible or not, then place that file in our servers where we would be waiting to confirm customer sign ups.

This gets the job done but provides a frustrating customer experience and bottleneck with our sales team. SFTP is limited because we would need to wait until our servers receive files from CPS Energy and vice-versa. In addition a customer could potentially go through the whole process - design their system, sign the customer agreement, and make a down deposit - only to find out they are ineligible for the program.

Improving Customer Experience and Informed Decision Making

After building the API, our customers have the option to provide their CPS Energy account number and ZIP code within the Big Sun Design Tool. Using Representational State Transfer (REST) HTTPS architecture, they receive instant verification that they are eligible for the program.

We did not stop there - if a customer is eligible we simultaneously pull their last 12 months of bills and consumption data. Now customers can see their actual monthly costs and customize their solar system size based on their energy goals. This is possible through a fast, secure, and reliable RESTful HTTPS architecture.

RESTful HTTPS is a type of software architecture that uses parameters (for instance an account number and ZIP code) to send and retrieve messages with other platforms. HTTP (HyperText Transfer Protocol) is a protocol that is used by the Internet to define the format of messages and how the messages are transmitted. HTTPS utilizes SSL (Secure Sockets Layer) to securely send messages. More information on the service:

Uses predictable, resource oriented URLs Has a built in HTTP capabilities for passing parameters via the API Responds with standard HTTP codes Returns results in JSON format

For the first time, San Antonio residents can learn about the Big Sun Community Solar program, design the perfect sized solar array and reserve panels within minutes using our Design Tool. If you want to talk with our sales team during the buying process - great, we’re available! But if you prefer to do your own research and then make the buying decision, the Design Tool allows you to do that too. With the APIs and Design Tool, we have customers going through the buying process in as little as twelve minutes!

What's Next

Using modern tech solutions and innovative business models, this joint effort in creating this API has opened the door to better and easier ways to provide renewable energy to everyone! RESTful allows for both horizontal and vertical scalability as new features can be added faster than traditional SFTP.

Be on the lookout for more blogs from us as we update you on the cool things Big Sun is working on!

Signing off, Andre